The invention relates to a sorting machine, especially for sorting mixtures of refuse, especially household rubbish, trade waste, industrial waste, refuse from demolition, waste from building sites, and also waste from wood or the like.
A sorting plant for sorting useful material has been published in the inventors' older German application No. 34 15 090 A1. In it, a sorting machine is disclosed which consists of a vibrating conveyor belt which is inclined transversely to the direction of conveying and rises in the direction of conveying, for separation of three-dimensional material to be sorted from two-dimensional material. There is no screening operation by means of a mesh.
The separation of dry waste, and sorting into individual components which can be re-utilized, causes great problems because of the severe entanglement of the waste that arrives. In particular, all types of screens tend to a greater or lesser extent to create blockages, because individual components can become stuck in the screening mesh. This is particularly the case for materials without any fixed structure or shape, such as stockings, scraps of cloth, string, and tape, which partly fall through the screening mesh and partly are retained by the remaining refuse. In this way the width of the mesh is automatically reduced.
For this reason, screening devices with meshes, or of screen form of any kind, can only be introduced into the treatment of refuse to a limited extent and with special measures. For this reason the way of separating materials is more or less restricted. Drum screens have indeed the advantage that the material introduced is continuously thrown on top of itself by the rotation, and hence is pulled apart. Nevertheless, drum screens are not suitable for sorting refuse, for again the meshes tend strongly to blockage by refuse components. Moreover the support and drive construction of drum screens needs axial space, which may be undesired.
From the totally foreign field of the sorting of hops, a device has been disclosed in U.S. Pat. No. 2,116,006, which consists of a circulating conveyor belt, that has a multiplicity of pockets. The operation of separation of the hop from the hop stem occurs by a brush shearing off and flinging away the hop stems projecting out of the pockets. On return of the belt, the remaining portions of hop fall into a container provided.
This device is not suited to the sorting of refuse, because a separating operation by means of a brush device is not possible. Moreover the pocket shape of the conveyor belt has merely the function of a holder for getting rid of the stems which stick up above it.